Heat 4 Tbsp. oil in a large skillet over medium heat. Add 4 garlic cloves and cook just until golden and sizzling. Add half the shrimp, placing them in one layer in the pan (if you crowd the shrimp, they will steam instead of fry). Sprinkle with salt.
Cook, turning once, just until lightly golden and pink around the edges, about 4 minutes total. With a slotted spoon, transfer the shrimp to a plate. Discard garlic cloves. Repeat with the remaining oil, garlic, and shrimp.
Stir in the shrimp, basil (if using) and parsley. Cook just until the shrimp are heated through. Serve immediately.
